Rotavirus

Rotavirus is an infection that causes diarrhea. It's the most common cause of diarrhea in infants and children worldwide, according to the Centers for Disease Control and Prevention. Before the development of a vaccine, most children in the United States had at least one bout with rotavirus by age 5.

Although rotavirus infections are unpleasant, you can usually treat this infection at home with extra fluids to prevent dehydration. Occasionally, severe dehydration requires intravenous fluids in the hospital. Dehydration is a serious complication of rotavirus and a major cause of childhood deaths in developing countries.

Vaccination can help prevent rotavirus infection in your infant. For older children and adults — who aren't as likely to develop serious symptoms of rotavirus — frequent hand-washing is the best line of defense.

A rotavirus infection usually starts within two days of exposure to the virus. Initial symptoms are a fever and vomiting, followed by three to seven days of watery diarrhea. The infection can cause abdominal pain as well.

In adults who are otherwise healthy, a rotavirus infection may cause only mild signs and symptoms or none at all.

When to see a doctor

Call your child's doctor if your child:

Has diarrhea for more than 24 hours

Has frequent episodes of vomiting

Has black or tarry stool or stool containing blood or pus

Has a temperature of 104 F (40 C) or higher

Seems lethargic, irritable or in pain

Has signs or symptoms of dehydration, including dry mouth, crying without tears, little or no urination, unusual sleepiness, or unresponsiveness

If you're an adult, call your doctor if you:

Can't keep liquids down for 24 hours

Have diarrhea for more than two days

Have blood in your vomit or bowel movements

Have a temperature higher than 103 F (39.4 C)

Have signs or symptoms of dehydration, including excessive thirst, dry mouth, little or no urination, severe weakness, dizziness on standing, or lightheadedness

Rotavirus is present in an infected person's stool several days before symptoms appear and for up to 10 days after symptoms subside. The virus spreads easily through hand-to-mouth contact throughout this time — even if the infected person doesn't have symptoms.

If you have rotavirus and you don't wash your hands after using the toilet — or your child has rotavirus and you don't wash your hands after changing your child's diaper or helping your child use the toilet — the virus can spread to anything you touch, including food, toys and utensils. If another person touches your unwashed hands or a contaminated object and then touches his or her mouth, an infection may follow. The virus can remain infectious on surfaces for weeks or longer if the area isn't disinfected.

Because there are many types of rotavirus, it's possible to be infected more than once, even if you've been vaccinated. However, repeat infections are typically less severe.

Rotavirus infections are common in children ages 3 to 35 months — particularly those who spend time in child care settings. Older adults and adults caring for young children have an increased risk of infection as well.

In the United States, the risk of rotavirus is highest in winter and spring.

There's no specific treatment for a rotavirus infection. Antibiotics and antivirals won't help a rotavirus infection. Usually, the infection resolves within three to seven days.

Preventing dehydration is the biggest concern. To prevent dehydration while the virus runs its course, drink plenty of fluids. If your child has severe diarrhea, ask your doctor about offering an oral rehydration fluid such as Pedialyte — especially if the diarrhea lasts longer than a few days.

For children, a rehydration fluid can replace lost minerals more effectively than can water or other liquids. Severe dehydration may require intravenous fluids in the hospital.

If you or your child needs to see a doctor, you'll likely see your primary care provider first. If there are questions about the diagnosis, your doctor may refer you to a gastroenterologist or an infectious disease specialist.

What you can do

Preparing a list of questions will help you make the most of your time with your doctor. Some questions you might want to ask your doctor or your child's doctor include:

What's the likely cause of these symptoms? Are there other possible causes?

Is there a need for tests?

What's the best treatment approach? Are there any alternatives?

Is there a need to take any medicine?

How can I ease the symptoms?

What to expect from your doctor

Some questions the doctor may ask include:

When did symptoms begin?

Have the symptoms been continuous, or do they come and go?

How severe are the symptoms?

Does anything seem to improve the symptoms?

What, if anything, appears to worsen symptoms?

What you can do in the meantime

Drink plenty of fluids. Stick with bland foods to reduce stress on your digestive system. If your child is sick, follow the same approach — offer plenty of fluids and bland food.

To reduce the spread of rotavirus, wash your hands thoroughly and often — especially after you use the toilet, change your child's diaper or help your child use the toilet. But even strict hand-washing doesn't offer any guarantees.

There are two vaccines offered against rotavirus:

RotaTeq. This vaccine is given by mouth in three doses, often at ages 2 months, 4 months and 6 months. The vaccine is not approved for use in older children or adults.

Although a few cases of intussusception — a rare but life-threatening form of intestinal blockage — were reported after vaccination with RotaTeq, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) found that the number of cases in vaccinated children was similar to the number of cases in unvaccinated children and concluded that the vaccine didn't increase a child's risk of intussusception. A similar anti-rotavirus vaccine (RotaShield) was pulled from the market in 1999 because of an association with intussusception.

If after vaccination your child has stomach pain, vomiting, diarrhea, blood in his or her stool, or a change in bowel movements, contact your doctor immediately.

Rotarix. This vaccine is a liquid given in two doses to infants at ages 2 months and 4 months. Clinical trials of the vaccine detected no increased risk of intussusception.